Re: [PATCH net-next 6/8] net/mlx5e: Introduce tc offload support

Jiri Pirko
2016-03-01T14:52:11Z

Tue, Mar 01, 2016 at 03:24:48PM CET, amir@vadai.me wrote:
>Extend ndo_setup_tc() to support ingress tc offloading. Will be used by
>later patches to offload tc flower filter.
>
>Feature is off by default and could be enabled by issuing:
> # ethtool -K eth0 hw-tc-offload on
>
>Offloads flow table is dynamically created when first filter is
>added.
>Rules are saved in a hash table that is maintained by the consumer (for
>example - the flower offload in the next patch).
>When last filter is removed and no filters exist in the hash table, the
>offload flow table is destroyed.

<snip>

>@@ -1880,6 +1883,17 @@ static int mlx5e_setup_tc(struct net_device *netdev, u8 tc)
> static int mlx5e_ndo_setup_tc(struct net_device *dev, u32 handle,
> __be16 proto, struct tc_to_netdev *tc)
> {
>+ struct mlx5e_priv *priv = netdev_priv(dev);
>+
>+ if (TC_H_MAJ(handle) != TC_H_MAJ(TC_H_INGRESS))
>+ goto mqprio;
>+
>+ switch (tc->type) {
>+ default:
>+ return -EINVAL;

-EOPNOTSUPP would be better here perhaps?

>+ }
>+
>+mqprio:
> if (handle != TC_H_ROOT || tc->type != TC_SETUP_MQPRIO)
> return -EINVAL;
>
>@@ -1963,6 +1977,13 @@ static int mlx5e_set_features(struct net_device *netdev,
> mlx5e_disable_vlan_filter(priv);
> }
>
>+ if ((changes & NETIF_F_HW_TC) && !(features & NETIF_F_HW_TC) &&
>+ mlx5e_tc_num_filters(priv)) {
>+ netdev_err(netdev,
>+ "Active offloaded tc filters, can't turn hw_tc_offload off\n");
>+ return -EINVAL;

This should not fail I believe. Just disable it in hw. I would even toss
away the rules if necessary.